1. Field
The present disclosure relates to an optical stimulation probe, more particularly to an optical stimulation probe with a reflecting surface for optically stimulating a subject and collecting signals in response thereto.
2. Description of the Related Art
Recently, studies are carried out actively on stimulation of the cranial nerves of a subject and detection and analysis of signals in response thereto, in order to treat brain diseases and understand the operation of the brain.
A neural probe that can be inserted into a subject is used to directly stimulate the cranial nerves of the subject and acquire information thereabout. Further, a microsized neural probe with an electrode array mounted thereon was developed to acquire as much information as possible resulting from the stimulation of the cranial nerves.
In general, an existing neural probe applies an electrical stimulus to the cranial nerves using electrodes assembled on the probe body so as to stimulate the cranial nerves. However, such electrical stimulation may damage the cranial nerves and, since the brain is composed of electrically conducting materials, it is impossible to apply a localized stimulus.
Thus, an optical stimulation probe capable of optically stimulating the cranial nerves using light and collecting response signals was introduced recently.
FIG. 1 schematically shows an existing optical stimulation probe 1.
As shown in FIG. 1, an existing optical stimulation probe 1 consists of a silicon probe body 2 to which an optical fiber 3 or an optical waveguide capable of transmitting light is attached. The optical stimulation probe 1 is inserted into a subject, e.g. a mouse.
On the probe body 2, an electrode 4 for collecting a response signal and an electrical conductor 5 electrical connected with the electrode 4 are provided.
An optical signal 6 generated from an external light source (not shown) is irradiated through the optical fiber 3 to stimulate a particular nerve 7, and a response signal 8 from the stimulated nerve 7 is collected by the electrode 4 for analysis of the neuronal activities.
In such an existing optical stimulation probe, since the path of the irradiated of the optical signal 6 is perpendicular to the electrode 4, the distance between the nerve 7 stimulated by the optical signal 6 from the electrode 4 is relatively long.
The cranial nerve signal has a small intensity and is easily amplified or attenuated due to noises. Considering that signals of better quality can be collected at the electrode when the distance from the electrode to the stimulated site is closer, it is needed to make the distance between the optically stimulated site and the electrode where the response signal from the stimulated site is collected as short as possible.